3 * \brief User-lock implementation for ARM
6 * (c) 2008-2009 Adam Lackorzynski <adam@os.inf.tu-dresden.de>,
7 * Alexander Warg <warg@os.inf.tu-dresden.de>
8 * economic rights: Technische Universität Dresden (Germany)
10 * This file is part of TUD:OS and distributed under the terms of the
11 * GNU General Public License 2.
12 * Please see the COPYING-GPL-2 file for details.
14 * As a special exception, you may use this file as part of a free software
15 * library without restriction. Specifically, if other files instantiate
16 * templates or use macros or inline functions from this file, or you compile
17 * this file and link it with other files to produce an executable, this
18 * file does not by itself cause the resulting executable to be covered by
19 * the GNU General Public License. This exception does not however
20 * invalidate any other reasons why the executable file might be covered by
21 * the GNU General Public License.
25 #include <l4/sys/utcb.h>
26 #include <l4/sys/atomic.h>
27 #include <l4/sys/compiler.h>
28 #include <l4/sys/ipc.h>
31 l4_usem_down_to(l4_cap_idx_t lock, l4_u_semaphore_t *sem, l4_timeout_s timeout) L4_NOTHROW
35 if (__builtin_expect(l4_atomic_add((long*)&(sem->counter), -1) >= 0, 1))
36 return l4_msgtag(0, 0, 0, 0);
38 l4_utcb_mr()->mr[0] = (l4_addr_t)sem;
40 register unsigned long _lock __asm__ ("r2") = lock | L4_SYSF_CALL;
41 register unsigned long _timeout __asm__ ("r3") = timeout.t;
42 register unsigned long _flags __asm__ ("r4") = 0;
43 register l4_msgtag_t _tag __asm__ ("r0") =
44 l4_msgtag(0 /*L4_SEMAPHORE_DOWN*/, 1, 0, 0);
47 ("@ l4_usem_down_to (semaphore block) \n\t"
62 [sys] "i" (L4_SYSCALL_INVOKE)
67 if (l4_msgtag_label(_tag) != L4_USEM_RETRY)
78 l4_usem_up(l4_cap_idx_t lock, l4_u_semaphore_t *sem) L4_NOTHROW
80 l4_atomic_add((long*)&(sem->counter), 1);
82 if (__builtin_expect(sem->flags == 0, 1))
83 return l4_msgtag(0,0,0,0);
85 l4_utcb_mr()->mr[0] = (l4_addr_t)sem;
87 register unsigned long _lock __asm__ ("r2") = lock | L4_SYSF_CALL;
88 register unsigned long _timeout __asm__ ("r3") = 0;
89 register unsigned long _flags __asm__ ("r4") = 0;
90 register unsigned long _tag __asm__ ("r0") =
91 l4_msgtag(1 /* L4_SEMAPHORE_UP_WITHOUT_YIELD */, 1, 0, 0).raw;
94 ("@ l4_usem_up (semaphore block) \n\t"
109 [sys] "i" (L4_SYSCALL_INVOKE)
111 "cc", "memory", "lr");
113 l4_msgtag_t t; t.raw = _tag;